Liquid clarifier



Oct. 30, 1951 w. c. BAUER 2,572,971

LIQUID CLARIFIER Filed Nov. 25, 1947 '7 Sheets-Sheet l jff i i SMM WW ML TER BAUER ma AIIIIII//A Elmwmp Oct. 30, 1951 w. c. BAUER y 2,572,971

LIQUID CLARIFIER A Filed Nov. 25, 1947 7 sheets-sheet 2 WAL T Ef? C BAUER Oct. 30, 1951 w. c. BAUER LIQUID CLARIFIER 7 Sheets-Sheet 3 Filed NOV. 25, 1947 l// ma Oct. 30, 1951 w. c. BAUER 2,572,971

` LIQUID CLARIFIER Filed Nov. 25, 1947 v'vsheets-sheet 4 Oct. 30, 1951 w. c. BAUER LIQUID CLARIFIER 7 Sheets-Sheet 5 Filed Nov. 25, 1947 Siwa/VWO@ WALTER C BAUER Oct. 30, 1951 w. c. BAUER 2,572,971

LIQUID CLARIFIER Filed Nov. 25, 194?v 7 Sheets-Sheer?l 6 3mm/vbo@ WALTER BAUER Oct. 30, 1951 w. c. BAUER 2,572,971

LIQUID CLARIF'IER Filed Nov. 25, 1947 '7 Sheets-Sheet 'i' N k w Q m *l 3 b Ik G3 QB i 32M Mae/W Patented Oct. 30, 1951 UNITED STATES PATENT OFFICE Application November 25, 1947', Serial No. 787,936

3 Claims.- (Cl. 210-184) This invention relates to a fluid purification system', and more particularly to a system for purifying the lubricating oil for an engine provided with a dry-sump crankcase and a'separate oil storage tank. The present vapplication is a continuation in part of my copending application Serial No. 259,026, ledFebruary 28, 1939, now abandoned, and Acopending application Serial No. 428,590, led January 28, 1942, now abandoned. This application discloses subject matter disclosed and claimed in Patent No. 2,447,680 which issued from application Serial No. 491,696, a division of application Serial No. 428,590.

Heretofore clarification systems for engines having a dry-sump crankcase have usually had the lters positioned on the pressure side of a pressure pump. This presents certain disadvantages inasmuch as it has necessitated a relatively heavy construction for thelter, and also increases the possibilities of leakage and injury to the purincation system, thus tending to impair the general eioency of the apparatus. Also, in event of failure of the purifying apparatus, oil pressure to the engine is cut on and the engine may be seriously injured.

Likewise, the prior systems have usually provided the ltering elements separate from the storage tank and also from each other. Obviously such arrangements necessitate an unnecessary amount of line connections, and here again the construction in general must be heavier than is necessary in the system which is the subject of this application. Likewise, special precautions must be taken in the case of such prior systems to avoid leakage.

Furthermore, the previous systems, in general, have provided no adequate means for luy-passing the clarication system when it is necessary to make replacements or repairs to the same, and the prior systems have been especially decient in providing by-passing which Will serve to filter the oil even while it is being by-passed around the primary ltering system.

An object of this invention is to provide a purification system which will overcome the above mentioned disadvantages and other disad-l vantages inhering in the systems of the prior art.

Another object of this invention is to provide a clarier system which may be positioned on the suction side of the pressure pump and the pressure side of a scavenger pump of a dry-sump crankcase motor. I

Yet another objectl of this invention is to provide an oil clarifier unit in which the filteringelements aren located Withinthe oil storage tank of lalubricating'system for a dry-sump`fcrankcase motor.

Still vanotherobfjectof my-invention is to provide rvan oil clarifier-unit composed of va plurality oflterin'g elements in which the operation of eachindividual' element orl group of elements may be readilydetermined.`

Astil'1-further objectfof this inventionis to provide'fanoil purifying system in Whichprovision'f-is made forv readily byepassing` the system when desired, and particularly'where :means are provided'ior'ltering the oil when -so-by-passed.

Withv these,- and other objects in view, my invention ing-eneral `embraces the concept vof prol vidinga purication system which may be positioned between the scavenger and pressure pumpsin the lubrication system for an engine of the dry-sump'crankcase type. positionthe filtering device Within the oil storage tank found in'the lubricating system for this pairing.

I`n the accompanying ydrawings. showingl two specific `embodiments of Vmy inventive concept,A and-inwhi'ch corresponding. numerals refer to the-same parts-z Figurel is a top plan view, with the cover removed, of a `clarifying. system uprovided with full flowstrainers and filtering. elements arranged in parallel.

Figure 2 is av longitudinal sectional view of the device shown in Figure l,..taken along-the line 2'-2Lrof Figure-1.

Figure-3V is alcrosssectional View takenfalong the -lin'e' @Xi- 3 of vFigure 2.

Figure 4 is. a;V detailed viewA of the discharge end-and associated valve` arrangement, ofy the. fullflow'rstrainers, takenalong the Vline 4'-4 of Figure 1.

- Figure 5 isla detailed view of the-by-pass valve taken along the'klinel-S of Fgurezl.

Figure 6- is a top plan View, with the cover` I preferably removed, of a modified form of filtering system in which the full ovv strainers and the filtering elements are arranged in series, said device being also provided with certain added features not shown in the form of system illustrated in Figures 1 5.

Figure 7 is a longitudinal sectional view taken along the line 'I-'I of Figure 6.

Figure 8 is a cross-sectional View taken along the line 8 8 of Figure 6.

Figure 9 is a detailed View of the by-pass arrangement, provided yvith straining means, taken along the line 9-9 of Figure 6.

Figure 10 is a view, from beneath, of the casting on which the relief valves, full ow strainers, and air-bleed strainer are mounted.

Figure 11 is a diagrammatic showing of the connections and valves for an installation of a device such as shown in Figures 6-10.

Figure 12 is a side elevational view of a motor upon Which is mounted the oil clarifier.

Figure 13 is an end view of the structure shown in Figure 12.

In order to illustrate the invention there is disclosed in Figures 12 and 13 of the drawings, a diesel motor generally designated by the letter A, which is operatively connected by a suitable mechanism to a pump unit, generally designated by the letter B. The pump unit B consists of a scavenger pump C and a pressure pump D.

VThe crankcase E of the engine is connected to the scavenger pump C by means of a conduit F through which oil is withdrawn from the base of the engine by the action of the scavenger pump C and forced through a conduit G into an oil purier, generally designated H which forms the basis of this invention.

After the oil has been purified in the unit H, in a manner which Will subsequently be described it is drawn through an outlet conduit I into the suction side of the pressure pump D and is then forced through a conduit J which connects the pressure side of the pump to the engine A.

Interposed in the conduit J is a cooler K. The

oil in returning to the engine is cooled while passing through the cooler by coming into heat exchange contact with Water circulated through the cooler by means connected to the nipples L. These means are not shown.

, Referring to the form of purifier device H set forth in Figures 1-5, there is provided a casing or oil storage tank, designated generally by the numeral I. This tank is divided longitudinally by a wall 2 terminating short of the top of the tank and Which forms, in eiect, a ltering compartment 3 and an oil reservoir 4 within the tank. The filtering compartment is provided with a top 5 which is suitably apertured to receive the necessary fittings Which support the ltering elements and when the fittings are secured in place, serves to maintain the filtering compartment separate and distinct from the oil reservoir 4, even though both compartments are located Within the oil storage tank. Stay bolts 6 may be employed to strengthen the dividing Wall 2. v

A screened cover I may be provided for the oil,

kmaintain the surge of the oil therein at a min- Referring more particularly to the individual filtering elements, it will be observed that in thev device of Figures 1-5 there are provided both full iioW strainers 9 and filter cartridges I I, the former to remove coarser material within the oil, and the latter to remove finer material. By full flow strainer is meant any type of metallic or fibrous screening material of relatively open mesh but still ne enough so that any dirt particle of sufiicient size to damage the engine in one passage through the engine is effectively Withheld. As previously mentioned, the full flow strainers and lter cartridges are mounted in parallel so that during one cycle in a normal operation, a portion of the oil will pass through the strainer elements and the remainder through the filter cartridges. The precise form of full flow strainer and the precise form of filter cartridge may be either of the conventional type or of any special design.

Referring particularly to Figures 2 and 4, in the arrangement there disclosed I have provided three pairs of full ovv strainers, each pair being supported by a casting I2 which is secured to the cover of the filter compartment, and such casting being disposed over a suitable aperture I3 provided in the cover. The casting is mounted in a Huid-tight t upon the cover by the use of gaskets or some other suitable means, and supports the full flow strainers 9 by receiving the threaded output nipple I4 of the strainer. The nipples are in uid communication with a chamber I5 in the casting, and the oil after passing through the full flow strainers 9 enters the chamber I5.

A spring loaded valve, designated generally I6, is mounted in the casting I2 and is composed of a' valve body Il provided With slots I8 which place the interior of the body in communication With the chamber I5. The valve head I9 is provided with a stem 2| and is urged against the valve seat A2li by means of spring 22. The spring 22 of course may be tensioned to afford the desired Working pressure for operation of the valve. This pressure is relatively low, and, when exceeded by the pressure of the oil in chamber I5, the valve is opened and the oil from chamber I5 passes therethrough. A splash plate 23 is provided at the discharge end of the valve to direct the discharged oil downwardly. It will be observed from Figure 1 that this oil is discharged onto the screens 1.

In the event that the load on the filter cartridges builds up beyond their designed capacity, which would principally result from one or more of the cartridges being rendered inoperative by virtue of clogging, etc., I have provided for by-passing some of the oil around the full flow strainers 9. These strainers, of course, can accommodate only a certain volume of oil, and such excess passes through a valve 24. This valve consists of a head 25 seated in the casting I2, a stem 26, a spring 21 and a nut 28. The nut 28 is provided with a socket in which the stem 26 may reciprocate, and also serves to hold the spring 21 operatively against the head 25. The nut 28 may be adjusted to provide the desired tension upon spring 21. When the pressure of the oil Within the lter compartment 3 exceeds the predetermined amount, the Valve 24 is opened, and the oil passes through channel 3 I past the valve, and

thence into the chamber I5 from which it is dis.

charged through valve I6.

The lter cartridges are suitably mounted upon plates 32 which are secured over apertures provided therefor in cover 5. Discharge spouts 33 are provided on the plates 32 and are in communication With the central bore of the cartridges I I. Therefore, oil, after passing through the carbridges.; II, is dischargedthrough the spouts 33.-,

ontothescreenncover I oftheoil compartment..

As*V stated above, I have disclosed full flow strainersrand, filter cartridges of conventional construction, in which the oily passes from the outer surface of the elements. radially -inwardly towardzthe center of the elements and thence upwardly` to the castingsy I2, in the case of the.

full flowstrainers, and to the plates 32 in the case of' the filterI cartridges.

design may be used in my unit, and there may be necessary certain slight modifications for certain types of strainersand cartridges.

changes that might be necessary if strainers and cartridges were employed in which the oil was filtered yby passing longitudinallythrough the strainers and cartridges, rather than inwardly radially as described above.

As` mentioned above, my unit may be placed.

intermediate the scavenger and pressure pumps in a: lubricating system, and the oil from the scavenger pump will enter the unit through connection 34 which is connected with the conduit G illustrated in Figure 12 and thence pass the lengthof the tank through line 35. A by-pass valve 36 is positioned in line 35, and, as best shownI in Figure 5, this valve may be manipulated to sendaall of the oil to the end of line 35, when in the position shown in Figure 5, or, if the valve is turned 90 clockwise from such position, the incoming oil will be discharged directly onto the screens and thus by-pass the filtering units and rI I. Consequently, if .it is desired to replace or'repair any of the units, this valve may be operated to by-pass the oil while such replacement or. repair is being made.

.A pipe 3'! extends from the line 35 to the base of the tank where it is connected to a manifold 38 provided with apertures 39 along its top. It will therefore be seen that the incoming oil, when not by-passed, is introduced to the filter compartment 3 adjacent its base and beneath the filter cartridges II and full ow strainers 9.

Arpipe connection 40 corresponding to conduit I in Figure 12 communicates with the oil reservoir 4 near the bottom thereof for flow of oil to the pressure pump of the engine. A capped discharge nipple 4| is provided at the base of the filter compartment 3 to permit a drainage thereof if occasion requires. A cover 42 is provided for the entire tank, and may be removed when it is desired to inspect or work upon the unit.

The operation of this device is believed to be apparent from the foregoing, and consists es'- sentially in the receipt of oil from the scavenger pump and thence the passage of such oil through lines4 35l and 31 and discharge of the same through manifold 38 into the filter compartment; Itxwill be observed that the manifold 38 provides forithe relative uniform` distribution of the incoming oil along the length of the filter compart ment,. and a portion of this oil passes throughthe full now strainers 9 and the remainder through theilter cartridges I I. The proportion of oil passingv through the strainers and cartridges will be determined by the setting of valves It and 24. To secure,as is the usual practice, a passage of the major portion of the oil through the full flow strainers, the valve I6 will Vbe set to operateV at a relatively low pressure.

loadon valve I6 may be increased which will thereby buildup the pressure within the filter:

However, it will be appreciatedxthat'strainers or cartridges of different- For instance,. any person skilled in the art would recognize the If it is desired to send more of the oil through the filter cartridges,` the compartment 3, and, `as a rresult of this, agreater. quantity of oil will pass through thefilter cartridge.

One. of thessalient features of this invention.

resides in the ability of an operator to easily determine the operation of each of the elements in4 the unit. For instance, merely by removing cover 42 the operator may observe the discharge from.v

the yvarious spouts 33 and also from the castings I2, and thus determine. whether any one of the elements is notoperating, or is operating, at aL reduced rate.

Referring now to the form of device shown inY Figures 6-10, itWill be noted that this device iS generally similar to the one previously described` vided, andthereI are also included certain otherl improvements as willbe described inmore detailY hereafter.

The oil storage tank, -designated generally IUI,

is providedv with a longitudinal partition |02 extending from one endlof tank IUI to the other.

The lower edge of partition |02 engages the bott-- tom ofthe coil storage tank IIlI vand the upper edge of the. partition is spacedfrom the. top-of the tank IIJI, in ,the mannerv bestshown in' Figure 8. reservoir |Ii3`in the storage tank :|0I. The spa-ce on the side of the partition |02 opposite fromreservoir |03 is a contaminatedoil compartment divided into oil compartmentsv land. I|I5i bya vertical wall ISG extending from partition |32'` to the side wall of the storage tank IIII'. Re-l ferring to Figure 7, it'will be seen that vertical wall |06 does notzextendto the bottom of tank# IBI and that the bottom of thecompartment '|04' is closed byY a horizontal plate |01 secured tothe;V partition |02, vertical wall V||I'6,.and the ,fw-falls of! the oil storage tank I Il I.

Depending from cover plate |08, within com'- partment I, is yabaiile I09-which subdivides.

that compartment into.` areas. IMA and HMB.

A casting I ismounted over the compartment' |04 which casting is providedwith a partition I I2 to form a compartment I I3 which is in communication with the area IMA. Mounted w-ithin compartment||3 isl awreduced fulliow strainerl I4, which may be of the'so-called Purolatorv This full fiow strainer isv type for convenience. carried by a mounting |I5 which is secured to the top of the casting I I I, and there is fitted intov the mountinga piece'of tubing IIB which ex tends to a point over the oil compartment |03..

as best shown in Figure 6.

The oil from the scavenger. pump enters the'4 unit throughr pipe II'I which empties into thel area IMA. The air that is contained in the -incoming oil is therefore free to escape; usually in= the form of foam, through thestrainer IUI-'and thence through the tubing IIB. AnyA oil that is entrapped in the air is thus directed to theoil reservoir I 03.

Referring to Figure 7, it will rbe noted that one of the walls` H8 tending to form compartment ||3 provides for a recess ||9 in the casting `I I I,

and inthe base of this recess, whichhappens to be the coverplate |08, two springloadedtrelief valves |2| arepositioned. It will be noted that that valves areadaptedzto open Vwhen the :prese:

In this case, however, the fullyow Partition |92 forms one Wall of an oil:

7 su're Within area 04A exceeds the predetermined pressure for which these valves are set. If the pressure in chamber |04 exceeds this predetermined limit, oil is discharged from that chamber into recess ||9 and then spills out over the plate |08 and thence into the oil reservoir |03.

Referring again to Figure 8, full now strainers |22 (two in number for the size unit here disclosed) are mounted in compartment |04 on the side |04B of balile |09. More specifically, each strainer |22 is rotatably mounted upon a cage |23 which is bolted within the casting and a rod rigidly secured to the strainer |22 extends through the cage |23 and through the top of the casting in a fluid-tight fit. A handle |24 is provided on the top of this rod to enable rotation of the strainer |22.

Rods |25 depend from the cover plate |08, which rods may carry Scrapers so that upon rotation of the strainer |22 solid and suspended material that is caught on the surface of the strainer may be removed therefrom and drained from the compartment |04. For purposes of this drainage, a discharge nipple |26 is provided at the base of compartment |04.

It will be noted that the strainer cages |23 are located in a compartment |21 formed in the casting and suitable holes are provided in the top of this compartment to permit the insertion of the strainers |22 and cages |23 therein. Flanged tops of the cages |23 support the strainer assembly and close the apertures in a fiuid-tight t.

Mounted in the base member |01 is a pipe |29 which extends to adjacent the cover plate |08, as best shown in Figure 8. A section of pipe |3| is adapted t extend through the base of casting and cover plate |08, and fits within the upper end of pipe |29.

The oil passes through strainers |22 and thence through the cage |23 into chamber |21. The oil may flow from chamber |21 down through the pipes "|3I and |29 to enter the cartridge compartment |05. It will be appreciated that the strainers |22 are materially larger than the strainer ||4, and in view of this fact, practically all of the oil received from the scavenger pump will pass through the strainers |22 and only-the,

air and entrained oil will escape through the strainer 4 and tube ||6.

Referring to Figures 6 and 8, it will be noted that a series of relief valves |32 are mounted in the compartment |21 of casting and these valves are so loaded that they operate only when a sucient pressure exists in compartment |21.

Such pressure, of course, would be the pressure existing within the cartridge compartment |05, which, in turn, would result from any impairment to the operation of the filter cartridges.

It will be noted that depending wall |06 ex-' tends below the base |01 of compartments |04 and to a point only a short distance above the base of the assembled tank. Mounted in this projection, and extending to the end wall of the cartridge compartment, is a manifold |33. It will be noted that there are a number of apertures |34 in this manifold which correspond to the number of lter cartridges, and cach aperture is located directly beneath the center of the corresponding cartridge. This feature of the present application, together with the air removal previously described, form the subject matter of my copending application Serial No. 430,961, iiled February 14, 1942, now Patent No. 2,401,039. However, briefly, the purpose of this arrangement of the apertures is to blanket the filter cartridges with the incoming oil. Such oil of course is heated, and consequently upon starting an operation, the cartridges are immediately subjected to the blanket of warm oil. This arment, therefore, obviates the lag in time which would be attendant upon heating the entire mass of oil within compartment |05 by the incoming oil. For a more detailed description of this operation, reference is made to my said copending application Serial No. 430,961, now Patent No. 2,401,039.

As in the case of the form of device shown in Figures 1-5, the specific form of full flow strainer and filter cartridge may be optional with the operator. However, I have diagrammatically shown in Figure 7 a cartridge |35 composed of l successive layers of filtering material. This may be formed by the use of molded cylindrical blocks of adsorbent material and cellulosic wrapping. Likewise, while each cartridge may be an integral element, if desired, in Figure '1 there are disclosed elements which are made up by axially securing two elements together by means of a rod |36 which extends through the central channel of the two assembled cartridges. A base plate |31 and a gasket-like spacer |38 are used, the tie rod |36 holding the base plate |31 against the bottom of the lower cartridge and securely clamping the two assembled cartridges between the base plate |31 and a cover plate |39. Into the cover plate |39 is screw-threaded a section of pipe |4|, such pipe communicating with the central bore of the assembled cartridge and with a recess |42 in the cover plate. Discharge tubes |43 extend from the recess |42 and serve to discharge the oil after passage through the filter into the oil storage compartment |03. The cover plate |39 is provided with two lugs |44, and a leaf spring |45 extends therebetween. The'tie rod |36 extends through the spring |45 to clamp the lter cartridge and cover plate in resiliently fixed position.

The cover |08 is provided with apertures to receive the respective filter cartridges, and the cover plates |39 are bolted over such apertures in fluid-tight t.

Referring to Figures 6 and 8, it will be observed that a cover |46 is provided for vthe oil compartment |03. Apertures are provided in this cover which are adapted to receive pocket screens |41 to permit the oil which is discharged from the relief valves or the filter cartridges to passinto the oil compartment. Above this cover plate an air vent |48 is provided through which the air from tube I6 may escape to the atmosphere.

Apertured baffle plates |49 are provided in the oil compartment to maintain the surge therein at a minimum. Oil is withdrawn from the oil compartment through discharge pipe |5| and then passes to the pressure pump from whence it is forced to the various bearings of the engines to be lubricated. As best shown in Figure '1, a capped drain pipe |52 is provided to drain the oil compartment when desired, and likewise a capped drain nipple |53 is provided for the purposes of draining the cartridge compartment. This oil may be centrifuged or otherwise cleaned and returned to the storage compartment.

As previously indicated, it is desirable, on occasions, to by-pass the oil around both the full flow strainers and lter cartridges in order to make repair or replacements to some of the ele--l ments, and in the form of device here under consideraton, I have disclosed a by-pass arrange- 9 ment which at the Sametime affords a substantial amount of straining of such by-passed oil. When the oil is to beqby-passed in this manner. it enters the unit through pipe |54, rather than through the inlet pipe I |1. A schematic ow diagram for both the normal and by-passing operations is set forth .-inFigure 11.

The by-pass device consists of a cylinder |55 which .is boltedto the end wall in communication with inlet pipe |54. Concentrically mounted within such cylinder. |55 vis .a second cylinder |56 having one end closed as at |51. This second cylinder carriesiin spaced relationship a cylindrical screen |58. Apertures |59 are cut into the Cylinder |56 through which oil may pass. As best `shown in Figure 9, the incoming. oil passes through screen |58 and thence throughy aperture |59 into the interior of the cylinder |56.

Mounted at the free end of the cylinder |56 is a cylinder |6| provided witha series of apertures |62 along its top side and with a plug v|63 at the end opposite the cylinder |56. Therefore the oil after passing through cylinder |56 entersthe cylinder |6| and is discharged through the apertures |62. cylinder I6 save along the bottom, and therefore all of the discharged oil is directed downwardly onto the top of cover |46.

It will be appreciated that by the obvious operation of the valves shown in Figure l1, the oil from the scavenger pump may be directed into the by-pass arrangement, and thence directly into the storage compartment. In this passage the coarser particles of suspended and solid matter will be removed by the cylindrical screen |58. While thus by-passing the oil, the full flow strainers and filter cartridges may be repaired or removed, and at the same time the danger of oil heavily loaded with objectionable matter is obviated.

A removable cover |65 is provided for the assembled unit so that, upon removal, the opera- .tion of the individual elements may ybe observed and such attention given them as may be necessary.

The operation of the device disclosed in Figures 6-10 is believed to be obvious. Normally, oil from the scavenger pump will enter the unit through pipe ||1. Any air that is included With such oil will rise in the compartment |04A in the ,form of foam, be separated by the strainer I4 and pass through the tubing ||6. The oil in such foam will flow into the oil compartment |03 through the pocket screens |41 and the air will be removed through air vent |48.

As indicated, inlet ||1 is on the side of baffle |09 in which the strainer I4 is located. The airfree oil passes beneath baille |09 to the opposite side, and then passes through strainer |22 into cage |23 and chamber |21. From chamber |21 the oil flows through pipes |3| and |29 into that portion of the tank beneath the base plate |01 of compartment |04. From there the oil enter's the manifold |33 and is discharged through apertures |34.

As previously mentioned, the oil from apertures |34 impinges against the base of the filter cartridges |35 and then ascends upwardly around each cartridge in the form of a lm or blanket.

This oil, even at the beginning of operations, will A splash plate v|64 surrounds the.;

1 lfO bore of each cartridge and thence upwardly and f out through the discharge spouts |43 and into the respective pocket screens. The oil in the oil compartment |03 is then picked up by the pressure pump and distributed to the various bearings of the engine.

The operation of the several relief valves is 4also believed to be apparent. For instance, if the full fiow strainers 22 should become clogged up, the pressure Within compartment |04 would thereby be increased. On such increase of pressure, valves |2| are actuated to permit the oil to :by-pass both the full flowstrainers |22 and the lter cartridges, such by-passed oil being ejected from recess I I9 and draining back onto the cover plate |46 of the .oil compartment and thence into .the body of oil in the storage compartment. On

the other hand, if vthe full ow strainers are operating enicently, but if `the cartridges should become clogged or, incapacitated for some other reason, pressure within the cartridge compartment |05 would be increased, and this increase in `pressure transmitted to the oil in chamber |21 of the casting. On such increase in pressure within chamber |21, valves |32 would be actuated to permit a icy-passing of theoil around theA filter cartridges and a discharge of such oil onto the cover plate |46.

And if it is desired to by-pass both the full now strainers and the cartridges, a filtering of the oil can still be secured by diverting the oil from the scavenger pump into the by-pass arrangement shown in Figures 6 and 9. In this case the oil enters through |54, is filtered through cylindrical screen |53, and then passes onto the cover plate |46 by way of the cylinders |56 and |62.

The advantages of` both forms of my device are believed to be apparent from the foregoing discussion, and consist essentially in the provision of filtering equipment intermediate the scavenger and pressure pumps of a lubricating system for dry-sump crankcase engines. It is also to be noted that this filtering takes place within the confines of an oil storage tank, thereby decreasing the amount of piping and connections necessary, not only With the consequent decrease in likelihood of leakage, but even if such leakage should occur, the oil would be recovered within the oil storage tank. Another salient feature of this device is the use of a multiplicity of filtering elements and the ability of an operator to readily observe the operation of the individual elements. The by-pass arrangement, particularly the one operated by valves |32, shown in Figures 6-10, is

believed to afford a relatively simple and efficient the precise details of construction herein set forth by way of illustration, as it is apparent that many changes and variations may be made therein, by those skilled in the art, without departing from the spirit of the invention, or exceeding the scope of the appended claims.

I claim: K

l. A liquid clarifier comprising a liquid storage tank having an inlet and an outlet, a partition in the tank separating a liquid reservoir communieating with the outlet from a clarifying compartment communicating with the inlet, means dividing the clarifying compartment into a filter com- -partment and a straining compartment, strainers mounted in the straining compartment and filters -mounted in the filter compartment, conduit means extending from the strainers to the filter compartment arranged to deliver liquid from the strainers to the filter compartment, said lters having discharge means delivering the liquid to the reservoir, and pressure responsive valve means in communication with the conduit means intermediate the strainers and filters adapted to open when the pressure drop across the lters exceeds a predetermined amount whereby oil from the strainers by-passes the lters.

2. Apparatus according to claim 1 in which each of the filters has a discharge tube terminating above the level of the liquid in the reservoir to allow observation of the condition of the liquid discharged from each of the lters to the 'foil reservoir.

3. A liquid clarifier' comprising a liquid storage tank having an-inlet and outlet, a partition in the storage tank separating a clean liquid reservoir therein from a liquid clarifying compartment, a vent maintaining said clean liquid reservoir at substantially atmospheric pressure,

said reservoir communicating with the outlet to the tank, strainers supported in the clarifying WALTER C. BAUER.

REFERENCES CITED The following references are of Vrecord in the file of thispatent:

UNITED STATES PATENTS Number Name Date 591,006- Parsons Oct. 5, 1897 1,246,850 Best NOV. 20, 1917 1,328,045 n Hills Jan. 13, 1920 1,906,417 Renfrew et al May 2, 1933 2,230,174 Beale Jan. 28, 1941 2,401,039 Bauer May 28, 1946 2,447,680 Bauer Aug. 24, 1948 

